EPDM not only tracks who has files checked out, but also what machine they are checked out on. You must have renamed the computer when you reinstalled Windows.
The easiest way is to log in that computer as the ADMIN user. He should be able to check in the files, if not, you could undo-checkout the files. (Make a copy of them first.)
Thanks for your assistant ,I can't check in by admin but.I found other opportunity with using
Undo Check out
Have a great day